Ebirah, Horror of the Deep

This film was originally written to star King Kong, as Rankin/Bass Productions had provided Toho with the license to the character in order to produce a tie-in film for their animated TV series King Kong (1966) (which was co-produced with another Japanese film studio, Toei). However, Rankin/Bass rejected the original screenplay for the film and Toho decided to replace King Kong with Godzilla. This explains some of the behavior of Godzilla in the film, such as being attracted to the Infant Island girl Daiyo. Toho and Rankin/Bass would then go on to co-produce King Kong Escapes (1967), which was more in line with what Rankin/Bass wanted.

At the end of the film, as Mothra flies back to Infant Island, the large net she is carrying with her feet with the humans inside it is missing.

For the Columbia/Tri-Star U.S. DVD release, which uses the original uncut Japanese version, the English language credits list the noted composer Masaru Satô as "Mararu Sato."

The MST3K version featured a Film Ventures-lensed print of the film that used a different title sequence made up of clips from Son of Godzilla.

Edited into All Monsters Attack (1969)